Many types of containers include a base, a body extending away from the base, a shoulder extending away from the body, a neck extending away from the shoulder, and a neck finish terminating the neck for accepting a closure. The neck finish typically includes circumferentially extending threads to cooperate with corresponding features of the closure, and a circular axial end surface to cooperate with a seal on an undersurface of the closure. U.S. Pat. No. 2,244,316 illustrates a glass container and closure of this type.
Other types of containers may be closed with peelable foil closures, which may include foil caps. The caps typically include circular base walls, and fully cylindrical skirts extending axially from the base walls. The foil caps are applied to neck finishes of the containers such that the base walls cover circular openings of the container neck finishes and the skirts extend along radially outer surfaces of the container neck finishes. Typically, only the base walls are adhered to top sealing surfaces of the container neck finishes. After application to a container, a skirt can become crimped to the container neck finish, thereby rendering the closure difficult to peel away froth the container. For example, when a user attempts to remove the foil closure from the container, the skirt deforms inwardly, creating a crimp around the neck finish. Such crimping creates resistance to upward pulling of the closure away from the container and artificially increases the peel force. Many approaches to facilitating removal of such closures from containers include improvements to material compositions of closure substrates, attachment layers, and/or adhesives.